Application of 256-slice computed tomography with low radiation doses in neonates with hypoxic-ischemic encephalopathy.

Hypoxic-ischemic encephalopathy (HIE), an injury or disease with lack of oxygen in the brain, may occur at any stage in childhood but the exact mechanisms that cause HIE remain unknown. In this study, 150 newborns suspected of having neonatal HIE and scheduled for a brain CT scan were randomly assigned to three equally sized groups as follows: standard dose group (120 kV, 250 mAsec), low dose group 1 (120 kV, 150 mAsec) and low dose group 2 (120 kV, 50 mAsec). All other acquisition parameters were the same in all groups. The CT dose index (CTDI), dose length product (DLP) and the image noise were compared among the three groups. The image quality was evaluated by blinded readers. The DLP of low dose group 2 was 19.3% of that of the standard dose group without a significant difference (P>0.05). The image noise of the low dose group 1 was greater than that of the standard dose group with a significant difference (P<0.01). Low dose scanning is feasible in the screening of HIE in neonates and is beneficial in protecting newborns against unnecessary radiation damage.